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The Athabasca Sand Dunes Provincial Park was created to protect the Athabasca sand dunes, a unique geophysical land feature in the boreal shield ecosystem of the province of Saskatchewan.〔(【引用サイトリンク】Athabasca Sand Dunes )〕 The Athabasca Sand Dunes are the most northerly active sand dune formation on Earth.〔 It first came to attention that it should be a protected area in 1969,〔 finally becoming the Athabasca Sand Dunes Provincial Wilderness Park on August 24, 1992. The park extends for 100 kilometres along the southern edge of Lake Athabasca. The sand dunes are 400 to 1,500 metres long, and their maximum height is approximately 30 metres. It is the most northerly sand dune area in the world, and accessible by float plane or boat only. The William River flows through the western section of the park ending in a large river delta. The McFarlane River flows through the far eastern section of the park. The park goes around the Fond du Lac 231 (First Nations Reserve) located on the McFarlane River. The First Nations village of Fond du Lac is located 44 km (27 miles) by air from the park's eastern boundary. ==Geology== The Athabasca Sand Dunes are estimated to be approximately 8,000 years old, formed near the end of the Last glacial period.〔 As glaciers receded, meltwater washed enormous quantities of sand, silt and sediment from local sandstone into Lake Athabasca, whose water level was at the time much higher than currently. As the lake level declined to its modern depth, the large sand deposits were revealed.〔 The sand dunes are quite unstable, being constantly shifted by winds, which push the dunes at the edges of the area into the surrounding forest. Evidence also suggests that fires have greatly influenced the winds shaping the dunes. Unlike the dunes closer to the lake, the southern dunes are in fact quite stable relative to other areas in the region.〔 Common desert geological features can be found in the region, such as eskers, desert pavement, and beach ridges.〔 In addition, portions of the Williams River in the region flow through braided channels in the sand. The dunes are generally parabolic in shape. The sand almost completely covers the underlying sandstone deposits; the bedrock is around 20 metres below ground on average.〔 The entire sandy region, including areas south of the dunes, serves as an enormous aquifer, which as a result significantly affects plant life and dune development. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Athabasca Sand Dunes Provincial Park」の詳細全文を読む スポンサード リンク
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